Premier League homegrown player rules may cause Mourinho to reassess who he targets this summer, and who he lets go.
Despite rumours that Terry, Lampard and Cole may all be leaving the club in the near future, Chelsea may not be so eager for the experienced trio to leave until they have some homegrown alternatives lined up.
If the three seasoned campaigners were all to leave Stamford Bridge this summer it would leave only Gary Cahill as a homegrown first team regular. Chelsea would then have to actively try and bring in players that were brought through the development systems in this country or submit a shorter squad list to the Premier League.
Premier League rules state that a club must have a minimum of eight homegrown players submitted as part of their 25-man squad list, or take any absences from those eight as a squad place lost. A club can have as many players 21 and under as they like regardless of whether they're homegrown or not. Chelsea currently have only four homegrown players, and therefore have a reduced over-21 squad list.
Of course there are other players currently out on loan that could be reintroduced to the squad by Jose Mourinho to sidestep these rules - Ryan Bertrand and Victor Moses being two of the more obvious candidates - but whether those two would be able to replace figures as important as Ashley Cole and Frank Lampard and the squad strength not suffer is another matter entirely.
The other problem for Mourinho next year will be that players like Mohamed Salah, currently eligible to play despite not being on the squad list because he is 21 or under, will turn 22 before the season begins, meaning the Portuguese will have to find a squad spot for the Egyptian.
It's the number one reason why young promising homegrown players are worth their weight in gold in the Premier League. Someone like Luke Shaw will take up one of those key four spots in a side's Premier League squad list as a valuable player in himself, rather than someone kept at the club solely for that purpose or having to submit a shorter list.
It's also why someone like Mat Daelhi of Cardiff, a hugely promising youngster but nowhere near a Chelsea first team spot, would be considered a transfer target over other more illustrious options. Of course, the player has ability, but he's a whole lot sweeter because of his schooling at Manchester United.